WATER FILTRATION. XIII. 



WATER FILTRATION. 



By J. M. Smail, m. inst. c.e. 



[Read before the Engineering Section of the Royal Society of N. S. Wales, 

 July 21, 1904.'] 



Filtration of water supply is a subject which the members 

 of the Engineering Section of the Royal Society have not up 

 to the present discussed, perhaps for the reason that it is 

 one which has not become prominent as a necessary factor 

 in the preservation of the health of the community of this 

 State. I have therefore, prepared a few notes on the sub- 

 ject, which I trust will be freely aud fully discussed. It 

 is proposed to deal with the question under two heads, first 

 European method or " Slow Filtration." Second, American 

 method, "Rapid or Mechanical Filtration." On the former 

 perhaps, it may be found that nothing new has been 

 advanced, yet on the other hand something of interest may 

 be found. The author has had an opportunity of seeing 

 both methods under working conditions. 



European Method or Slow Filtration. 

 When filtration of water is brought up, the mind invari- 

 ably turns to what is being carried out in connection with 

 the water supply of London, which may well be termed the 

 Metropolis of the World. Without wearying you with the 

 history of the development of filtration of water supplies it 

 will be sufficient to state that the question did not take a 

 concrete form until the year 1828, when the late Mr. James 

 Simpson installed the system in connection with the Chelsea 

 Waterworks, which was followed by all the companies 

 drawing water from the Thames, and by all the large cities 

 and towns in Great Britain and Ireland with two notable 



